Fluid recirculation system for an automatic washer

Abstract

An automatic washer having an improved recirculation system wherein wash liquid is collected in a sump and recirculated onto the clothes load in a first recirculation loop and wash liquid is recirculated from a mixing tank through conduits and a pump back to the mixing tank to effect thorough mixing of the wash liquid. The mixing tank can be selectively connected to the first recirculation loop to direct selected amounts of wash fluid into the wash load, and a sensor is provided to sense the amount of wash fluid in the sump to assure that a sufficient amount of wash fluid is being recirculated into the clothes load.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows: 
     
       1. An automatic washing machine comprising an imperforate wash tub;   a wash basket positioned within said wash tub defining a wash zone;   a fresh water inlet; and   a recirculation system comprising: a collection zone for receiving wash liquid from said wash zone and being spaced below said wash basket;   a pump having a suction inlet communicating via a first fluid conduit with said collection zone;   a recirculation nozzle selectively communicating with a discharge outlet of said pump via a second fluid conduit, said nozzle being positioned to direct wash fluid into said wash zone;   a mixing zone for receiving and storing a supply of detergent and fresh water, said mixing zone selectively communicating with said suction inlet via a third fluid conduit and selectively communicating with a discharge outlet of said pump via a fourth fluid conduit;   sensing means associated with said collection zone for sensing the presence of wash liquid within said collection zone; and   control means for admitting wash liquid to said wash zone in response to a predetermined condition of said sensing means.     
     
     
       2. An automatic washing machine according to claim 1, wherein said collection zone comprises a sump area in a bottom wall of said wash tub. 
     
     
       3. An automatic washing machine according to claim 1, wherein said collection zone is spaced a sufficient distance from said wash basket and has a sufficient capacity such that it can collect a sufficient amount of wash liquid therein to present a constant supply of wash liquid to said pump while preventing said collected wash liquid from coming in contact with said basket while in said collection zone. 
     
     
       4. An automatic washing machine according to claim 1, wherein said selective communication between said nozzle and said pump comprises a valve positioned in said second fluid conduit operated by said control means. 
     
     
       5. An automatic washing machine according to claim 1, wherein said mixing zone comprises a mixing tank secured to an exterior surface of said tub. 
     
     
       6. A fluid recirculation system for an automatic washer comprising: a collection zone for wash liquid;   a pump having a suction inlet communicating via a first fluid conduit with said collection zone;   a recirculation nozzle selectively communicating with a discharge outlet of said pump via a second fluid conduit;   a mixing zone for receiving a supply of detergent and fresh water, said mixing zone having an outlet selectively communicating with said suction inlet via a third fluid conduit and an inlet selectively communicating with a discharge outlet of said pump via a fourth fluid conduit; and   sensing means associated with said collection zone for sensing the presence of wash liquid within said collection zone; and   control means for admitting wash liquid to said wash zone in response to a predetermined condition of said sensing means.   
     
     
       7. A fluid recirculation system for an automatic washer according to claim 6, wherein said sensing means comprises a pair of conductivity probes, each comprising an electrode with a tip exposed in said collection zone to detect the presence of wash liquid by measuring the conductivity of the path between said two electrode tips. 
     
     
       8. A fluid recirculation system for an automatic washer according to claim 6, wherein said sensing means comprises a pressure dome sensor positioned in said collection zone to detect the presence of wash liquid by measuring the pressure applied against said pressure dome. 
     
     
       9. A fluid recirculation system for an automatic washer according to claim 6, wherein said sensing means comprises a thermistor system located in said collection zone to detect the presence of wash liquid by sensing the temperature of a sensor element. 
     
     
       10. An automatic washing machine comprising an imperforate wash tub;   a wash basket positioned within said wash tub defining a wash zone; and   a recirculation system having at least two recirculation loops comprising: a collection zone for wash liquid spaced below said wash basket and communicating with said wash zone;   a pump having a suction inlet communicating via a first fluid conduit with said collection zone;   a recirculation nozzle selectively communicating with a discharge outlet of said pump via a second fluid conduit, said nozzle being positioned to direct wash fluid into said wash zone;   a mixing zone for receiving a supply of detergent and fresh water, said mixing zone selectively communicating with said suction inlet via a third fluid conduit and selectively communicating with a discharge outlet of said pump via a fourth fluid conduit; said collection zone, pump, recirculation nozzle and first and second fluid conduits comprising a first loop of said recirculation system passing through said wash zone, and said mixing zone, pump and third and fourth fluid conduits comprising a second loop of said recirculation system entirely outside of said wash zone.       
     
     
       11. An automatic washing machine according to claim 10, wherein said mixing zone can selectively communicate with said first loop via said third fluid conduit to admit wash fluid from said mixing zone into said first loop. 
     
     
       12. An automatic washing machine according to claim 10, wherein said collection zone comprises a sump area in a bottom wall of said wash tub. 
     
     
       13. An automatic washing machine according to claim 10, wherein said collection zone is spaced a sufficient distance from said wash basket and has a sufficient capacity such that it can collect a sufficient amount of wash liquid therein to present a constant supply of wash liquid to said pump while preventing said collected wash liquid from coming in contact with said basket while in said collection zone. 
     
     
       14. An automatic washing machine according to claim 10, wherein said selective communication between said nozzle and said pump comprises a valve positioned in said second fluid conduit operated by said control means. 
     
     
       15. An automatic washing machine according to claim 10, further including a sensing means associated with said collection zone for sensing the presence of wash liquid within said collection zone and control means for admitting wash liquid to said wash zone in response to a predetermined condition of said sensing means.